/*
* Copyright (C) 2001-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <proc/scheduler.h>
#include <proc/thread.h>
#include <proc/task.h>
#include <mm/heap.h>
#include <mm/frame.h>
#include <mm/page.h>
#include <arch/asm.h>
#include <arch.h>
#include <synch/synch.h>
#include <synch/spinlock.h>
#include <synch/waitq.h>
#include <synch/rwlock.h>
#include <cpu.h>
#include <func.h>
#include <context.h>
#include <list.h>
#include <typedefs.h>
#include <time/clock.h>
#include <list.h>
#include <config.h>
#include <arch/interrupt.h>
#include <smp/ipi.h>
#include <arch/faddr.h>
#include <arch/atomic.h>
#include <memstr.h>
char *thread_states[] = {"Invalid", "Running", "Sleeping", "Ready", "Entering", "Exiting"}; /**< Thread states */
spinlock_t threads_lock;
link_t threads_head;
static spinlock_t tidlock;
__u32 last_tid = 0;
/** Thread wrapper
*
* This wrapper is provided to ensure that every thread
* makes a call to thread_exit() when its implementing
* function returns.
*
* interrupts_disable() is assumed.
*
*/
static void cushion(void)
{
void (*f)(void *) = THREAD->thread_code;
void *arg = THREAD->thread_arg;
/* this is where each thread wakes up after its creation */
before_thread_runs();
spinlock_unlock(&THREAD->lock);
interrupts_enable();
f(arg);
thread_exit();
/* not reached */
}
/** Initialize threads
*
* Initialize kernel threads support.
*
*/
void thread_init(void)
{
THREAD = NULL;
nrdy = 0;
spinlock_initialize(&threads_lock);
list_initialize(&threads_head);
}
/** Make thread ready
*
* Switch thread t to the ready state.
*
* @param t Thread to make ready.
*
*/
void thread_ready(thread_t *t)
{
cpu_t *cpu;
runq_t *r;
ipl_t ipl;
int i, avg, send_ipi = 0;
ipl = interrupts_disable();
spinlock_lock(&t->lock);
i = (t->priority < RQ_COUNT -1) ? ++t->priority : t->priority;
cpu = CPU;
if (t->flags & X_WIRED) {
cpu = t->cpu;
}
spinlock_unlock(&t->lock);
/*
* Append t to respective ready queue on respective processor.
*/
r = &cpu->rq[i];
spinlock_lock(&r->lock);
list_append(&t->rq_link, &r->rq_head);
r->n++;
spinlock_unlock(&r->lock);
atomic_inc(&nrdy);
avg = nrdy / config.cpu_active;
spinlock_lock(&cpu->lock);
if ((++cpu->nrdy) > avg) {
/*
* If there are idle halted CPU's, this will wake them up.
*/
ipi_broadcast(VECTOR_WAKEUP_IPI);
}
spinlock_unlock(&cpu->lock);
interrupts_restore(ipl);
}
/** Create new thread
*
* Create a new thread.
*
* @param func Thread's implementing function.
* @param arg Thread's implementing function argument.
* @param task Task to which the thread belongs.
* @param flags Thread flags.
*
* @return New thread's structure on success, NULL on failure.
*
*/
thread_t *thread_create(void (* func)(void *), void *arg, task_t *task, int flags)
{
thread_t *t;
__address frame_ks, frame_us = NULL;
t
= (thread_t
*) malloc(sizeof(thread_t
)); if (t) {
ipl_t ipl;
spinlock_initialize(&t->lock);
frame_ks = frame_alloc(FRAME_KA);
if (THREAD_USER_STACK & flags) {
frame_us = frame_alloc(FRAME_KA);
}
ipl = interrupts_disable();
spinlock_lock(&tidlock);
t->tid = ++last_tid;
spinlock_unlock(&tidlock);
interrupts_restore(ipl);
memsetb(frame_ks, THREAD_STACK_SIZE, 0);
link_initialize(&t->rq_link);
link_initialize(&t->wq_link);
link_initialize(&t->th_link);
link_initialize(&t->threads_link);
t->kstack = (__u8 *) frame_ks;
t->ustack = (__u8 *) frame_us;
context_save(&t->saved_context);
context_set(&t->saved_context, FADDR(cushion), (__address) t->kstack, THREAD_STACK_SIZE);
the_initialize((the_t *) t->kstack);
ipl = interrupts_disable();
t->saved_context.ipl = interrupts_read();
interrupts_restore(ipl);
t->thread_code = func;
t->thread_arg = arg;
t->ticks = -1;
t->priority = -1; /* start in rq[0] */
t->cpu = NULL;
t->flags = 0;
t->state = Entering;
t->call_me = NULL;
t->call_me_with = NULL;
timeout_initialize(&t->sleep_timeout);
t->sleep_queue = NULL;
t->timeout_pending = 0;
t->rwlock_holder_type = RWLOCK_NONE;
t->task = task;
t->fpu_context_exists=0;
t->fpu_context_engaged=0;
/*
* Register this thread in the system-wide list.
*/
ipl = interrupts_disable();
spinlock_lock(&threads_lock);
list_append(&t->threads_link, &threads_head);
spinlock_unlock(&threads_lock);
/*
* Attach to the containing task.
*/
spinlock_lock(&task->lock);
list_append(&t->th_link, &task->th_head);
spinlock_unlock(&task->lock);
interrupts_restore(ipl);
}
return t;
}
/** Make thread exiting
*
* End current thread execution and switch it to the exiting
* state. All pending timeouts are executed.
*
*/
void thread_exit(void)
{
ipl_t ipl;
restart:
ipl = interrupts_disable();
spinlock_lock(&THREAD->lock);
if (THREAD->timeout_pending) { /* busy waiting for timeouts in progress */
spinlock_unlock(&THREAD->lock);
interrupts_restore(ipl);
goto restart;
}
THREAD->state = Exiting;
spinlock_unlock(&THREAD->lock);
scheduler();
}
/** Thread sleep
*
* Suspend execution of the current thread.
*
* @param sec Number of seconds to sleep.
*
*/
void thread_sleep(__u32 sec)
{
thread_usleep(sec*1000000);
}
/** Thread usleep
*
* Suspend execution of the current thread.
*
* @param usec Number of microseconds to sleep.
*
*/
void thread_usleep(__u32 usec)
{
waitq_t wq;
waitq_initialize(&wq);
(void) waitq_sleep_timeout(&wq, usec, SYNCH_NON_BLOCKING);
}
/** Register thread out-of-context invocation
*
* Register a function and its argument to be executed
* on next context switch to the current thread.
*
* @param call_me Out-of-context function.
* @param call_me_with Out-of-context function argument.
*
*/
void thread_register_call_me(void (* call_me)(void *), void *call_me_with)
{
ipl_t ipl;
ipl = interrupts_disable();
spinlock_lock(&THREAD->lock);
THREAD->call_me = call_me;
THREAD->call_me_with = call_me_with;
spinlock_unlock(&THREAD->lock);
interrupts_restore(ipl);
}